如何使用ReactJs在前台获取子文档数据mongoose

import React, { Component } from 'react';
import mongoose from 'mongoose';

class MyComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      subDocuments: []
    };
  }

  componentDidMount() {
    mongoose.connect('mongodb://localhost/mydatabase', { useNewUrlParser: true });

    const SubDocumentModel = mongoose.model('SubDocument', new mongoose.Schema({
      // 定义子文档的结构
      name: String,
      age: Number
    }));

    SubDocumentModel.find({}, (err, subDocuments) => {
      if (err) {
        console.error(err);
      } else {
        this.setState({ subDocuments });
      }
    });
  }

  render() {
    const { subDocuments } = this.state;

    return (
      <div>
        <h1>子文档数据</h1>
        <ul>
          {subDocuments.map((subDocument, index) => (
            <li key={index}>{subDocument.name} - {subDocument.age}</li>
          ))}
        </ul>
      </div>
    );
  }
}

export default MyComponent;